Fix accessibility issue with RestrictedSwitchPreference

This fixes an issue where the summary of the RestrictedSwitchPreference
got changed to the default summary when accessbility is enabled and the
preference that is disabled by an admin is clicked.

Bug: 363003265
Test: manual
Test: atest RestrictedSwitchPreferenceTest
Flag: EXEMPT bug fix
Change-Id: I6adc76ee12ea6697600c9979dc2c427376e2ef9e